[0001] The invention concerns a lock having a locking member displaceable between a locking
position and a release position.
[0002] With certain applications of such a lock, circumstances may occur which render it
desirable for safety reasons that the locking member of the lock is displaced automatically,
i.e. without hand operation, from the locking position to the release position. An
important example of such an application forms the lock of a buckle fastening of a
safety belt for motor-cars. In case the motor-car is submerged or catches fire as
a result of a traffic accident, it may easily occur that the occupant cannot open
the buckle fastening himself through his confusion or because he is stunned by the
shock, which impedes rescue efforts. The same applies in case the motor-car door is
locked at the inside and therefore cannot be opened from the outside. Naturally also
other critical conditions are conceivable wherein it is desired that a lock is automatically
opened or a latch locking effected by hand or by key is removed.
[0003] French patent 2,264,691 discloses a lock incorporated in a safety belt of a vehicle,
in which lock extend the two free belt ends and each lock being provided with a spring-loaded,
water-soluble cushion. In case the vehicle is submerged, the cushion will be dissolved,
so that the spring allowsthat at least one of the belt ends can freely move out of
the lock.
[0004] This prior art device, however, has the drawback that use is made of a separate lock
to be incorporated in the safety belt. Furthermore the water-soluble material is continuously
loaded.
[0005] It is the object of the invention to provide a lock of the above-described type and
which is devoid of these drawbacks.
[0006] The lock according to the invention has the feature that it is provided with a safety
device for automatically unlocking the locking member upon a critical change of a
given ambient condition, which safety device comprises at least one feeler member
usually unloaded and responsive to the change of condition concerned and being provided
with an unlocking element which is movable under spring action from a retracted, rest
position, wherein said element does not influence the locking member of the lock,to
an operative condition, wherein said element displaces the locking member to the release-,
position, said unlocking element being retained in the rest position by a catch co-acting
with the feeler member, which catch is operated when the feeler member responds to
a change of condition and then releases the unlocking element.
[0007] According to an important embodiment of the invention, the feeler member comprises
a liquid-absorbing swelling body which presses the catch to the release position during
its swelling by liquid absorption. To this effect according to the invention the swelling
body may be accommodated in a chamber bounded at one side by a slide, which slide
engages the catch. If consequently the swelling body contacts a liquid, e.g. in that
it is submerged, the swelling-up swelling body pushes the slide aside, so that the
catch is operated and the unlocking element through the effect of the spring engaging
thereon can move the lock latching member to the release position.
[0008] According to an embodiment of the invention the lock is a buckle fastening with snap
effect, in particular for a safety belt for motor-cars or the like, whereby the safety
device together with the feeler member designed as a swelling body is accommodated
in the buckle housing. If consequently the motor-car is submerged so that the swelling
body comes into contact with water, the buckle fastening will be automatically opened.
As a result there is produced a compact construction, while moreover the feeler member
is usually unloaded.
[0009] According to a different embodiment of the invention, the lock is a door lock, in
particular for a motor-car door, of the type that is closable at one side through
a key and at the other side having an actuating member, such as a sliding pin provided
with a hand knob, by means of which the lock can be locked and unlocked from this
side, whereby the unlocking element of the safety device being under spring pressure,
upon actuation of said device, operates the actuating member of the door lock when
said pin is in the lock latching position. If consequently the occupant of a motor-car
has closed the door by depressing the lock sliding pins at the inside, said sliding
pins, in case the motor-car is submerged, will be automatically pressed to the unlocking
position by the swelling bodies of the associated safety devices, so that the doors
can be opened from the outside in case of a rescue operation.
[0010] According to the invention it is favourable when the safety device comprises besides
the swelling body also as second feeler member a temperature-responsive member for
unlocking the locking member of the lock. It is achieved thereby that also in case
of fire the locking member is displaced to the release, position, i.e. the buckle
fastening will be opened or the door lock is unlocked. This embodiment with temperature
increase-responsive safety device may also be applied e.g. to door locks of hotel
rooms and the like, so that in case of fire these can be opened from the outside.
It is observed in this respect that German Offenlegungs- schrift 2,653,124 discloses
per se a temperature-responsive feeler member for a safety belt, wherein use is made
of electric connections, which have the drawback that they can be easily put out of
operation, while in the device according to the invention use is made of an entirely
mechanical disconnecting mechanism.
[0011] Some embodiments of the lock with safety device according to the invention will now
be described, by way of example, with reference to the accompanying drawings, while
also other preferred constructive features will be discussed.
[0012]
Fig. 1 is a perspective view of a buckle fastening for a safety belt for motor-cars
and the like, wherein the safety device is accommodated;
Fig. 2 is a top view and partly a horizontal cross-section of the buckle fastening
of Fig. 1;
Fig. 3 is a cross-section on the line III-II of Fig. 2;
Fig. 4 is a dross-section on the line IV-IV of Fig. 2;
Fig. 5 is a cross-section on the line V-V of Fig. 2;
Fig. 6 is a vertical cross-section of a safety device for a motor-car door lock, of
which only the locking sliding pin is drawn; and
Fig. 7 is a cross-section on the line VII-VII of Fig. 6.
[0013] The buckle fastening for a safety belt shown in Figures 1-5 has a flat housing 1
with a cover 2 screwed thereon, which housing is secured to a carrier plate 3 projecting
with a lip portion 4 beyond the housing and having therein a fixing hole 5 for the
buckle. At the end facing away from the lip portion 4, the housing has an end wall
6 which releases between its lower edge and the housing bottom an insert slot 7'for
a flat buckle tongue 8, having at the rear side a slotted hole 9 for attachment of
the belt, not shown, and at its leading insert end a locking opening 10.
[0014] In the housing 1 there is secured a framework comprising flat longitudinal bars 11
(Fig. 2), which are rigidly connected besides by the end wall 6 also by transverse
walls 12 and 13. In pivot openings 14 of the longitudinal bars 11 there is rotatably
supported a locking body 15, which has a guide tongue 16 for the buckle tongue 8 projecting
rearwardly through the insert slot 7, at the bottom side a downwardly extending locking
cam 17 fitting in the locking opening 10 of the buckle tongue 8 and at the top side
a hook-shaped portion 18.
[0015] On the locking body 15 acts a leaf spring 19 attached at the one longitudinal bar
11, which spring keeps the locking body pressed in the closure position,.wherein the
locking cam 17 with its leading edge abuts against the bottom of the housing 1. Thus
there is formed a buckle fastening with snap effect in that the buckle tongue 8 during
insertion in the insert slot 7 finds guidance between the guide tongue 16 of the locking
body 15 and the housing bottom and subsequently also underneath a pin 20, thereby
pressing the cam 17 in upward direction against the leaf spring 19 until this can
fall in the locking opening 10 of the buckle tongue, engaging behind the leading edge
of said opening 10 (Figures 3 and 5).
[0016] For manually lifting the locking body 15 serves a lever 22 supported pivotally about
a pivot pin 21 in an opening in the transverse wall 13, said lever engaging with one
end underneath the hook-shaped portion 18 of the locking body 15. Behind a rectangular
opening 23 cut out in the cover 2 there is present a finger pressure plate 24 which
on the one end is rotatably secured to the cover 2 by a pivot pin 25 and which carries
at its opposite edge a downwardly projecting fork-shaped pressure member 26 which
engages about the respective end of the lever 22. Between the bottom of the housing
1 and the finger pressure plate 24 there is positioned a pressure spring 27 (Fig.
3) which keeps said plate pressed against the bottom side of the cover 2. By a pressure
with the finger on the plate 24 against the action of the spring 27 it is thus possible
to rotate the lever 22 through the pressure member 26 to a position wherein said lever,
by means of the hook-shaped portion 18, swivels the locking body 15 to the unlocked
position releasing the buckle tongue 8.
[0017] The above described parts of the buckle fastening are of an embodiment conventional
for such fastenings.
[0018] According to the invention there is now accommodated in the buckle housing 1 a safety
device ensuring that the locking body 15 automatically unlocks the buckle tongue 8
when the buckle housing is exposed to the effect of water or a high temperature.
[0019] At the back side of the buckle housing 1 there is formed a chamber 28 which is bounded
at the outer side by a detachable back plate 29 constituting the back wall of the
housing 1 and secured by a screw 29rand provided with holes 30, and at the inner side
by an L-shaped slide 31, which slide 31 is guided by transverse guide pins 32 disposed
between the longitudinal bars 11. In the chamber 28 there is positioned a cylindrical
swelling body 33 of a suitable cellulose which lies enclosed with slight play between
the wall 29 and the slide 31 and, if desired, as drawn, may be kept by a spring 34
in slightly clamped relationship. Upon removal of the back plate 29, the chamber 28
is accessible for insertion of the swelling body 33.
[0020] In fitting holes in the transverse walls 12 and 13 there is slidably guided an unlocking
rod 35 which in the retracted rest position shown in Figures 2 and 3 engages with
its beveled leading end 36 with slight play underneath the edge of the hook-shaped
portion 18 of the locking body 15. About the rod 35 there is positioned a helical
spring 37 which on the one end finds support against the transverse wall 12 and on
the other end against a sleeve 57 fixed onto the rod 35, thus trying to press the
rod 35 forwardly. At the rear end of the rod 35 there is affixed a plate 38 which
is guided between an upper guide roller 40 carried by supports 39 and two lower guide
rollers or pins 41 and 42 which are supported in the longitudinal bars 11. The guide
pin 42 likewise forms the pivot pin for a two-armed rotary catch 43, the upper, bent-
arm of which is inserted in an opening 44 of the plate 38 and the lower arm of which
presses against the slide 31. The catch 43 thus prevents the unlocking rod 35 from
sliding forwards through the effect of the spring 37, whereby the unlocking pawl retains
the slide 31 in its rearward position under the effect of the spring pressure, in
which position it abuts against the front guide pin 32. If, however, the buckle fastening
comes to lie under water and this water can penetrate through openings 30 into the
chamber 28, the swelling body 33 will rapidly swell and press the slide 31 forwardly
through its expansion, so that the catch 43 is rotated away from the opening 44 and
thus releases the unlocking rod 35. As a result the spring 37 can press the rod 35
forwardly and said rod can lift with its end the locking body 15 until the buckle
fastening is opened.
[0021] In the housing cover 2 there is provided yet an access opening 46 covered by a detachable
closure plate 45, enabling, after operation of the unlocking rod 35, to slide same
back to its starting position and to position the catch 43 again in the locking position
by means of a suitable tool.
[0022] The safety device accommodated in the buckle housing 1 furthermore comprises a bimetal
element 47 (Fig. 4), which is fixed with its ends in a holder 48,which holder is secured
by screws 49 against the outer side of one of the longitudinal rods 11, so that the
holder and the bimetal lie incorporated in the space between the longitudinal rod
11 and the adjacent housing sidewall.. Furthermore two nuts 50 are welded against
the rod 11 and wherein are screwed adjusting screws 51 pressing against the ends of
the holder, enabling to accurately adjust the device by a slight bending of the elongate
holder 48. The bimetal element 47 carries in the center a downwardly extending catch
in the form of a pin 52. Underneath the bimetal element 47 there extends a second
unlocking rod 53 which is guided slidably in holes in ends of the transverse walls
12 and 13 projecting beyond the longitudinal bar 11 and engaging with a beveled end
54 with some play underneath a support member 55 of the locking body 15 projecting
through the pivot opening 14 of the longitudinal bar 11. Figure 4 shows that said
opening 14 is formed in such a way that the support member 55 is adapted to perform
a pivoting movement therein. About the unlocking rod 53 there is positioned a helical
spring 56 which lies enclosed between the transverse wall 13 and a sleeve 58 affixed
onto the rod 53 and thus trying to press the rod 53 forwardly. In the rest position
shown the unlocking rod 53, however, is locked in that the locking pin 52 is inserted
in a transverse bore hole 59 of the rod 53.
[0023] The bimetal element 47 is designed in such a way that when heated said element deflects
upwardly in the center, thereby pulling the locking pin 52 from the hole 59 of the
unlocking rod 53 so that at a given strongly increased critical ambient temperature,
the pin 52 releases the unlocking rod 53 so that the spring 56 can press said rod
with its end 54 underneath the portion 55 of the locking body 15 for unlocking the
buckle fastening. In the sidewall of the housing 1 extending along the bimetal 47
there are provided ventilation holes 60 (Fig. 1).
[0024] The safety device shown entirely by 61 in Figures 6 and 7 serves for unlocking a
door lock of a motor-car door in case of calamity. The door lock may have a conventional
design and is of the type that is lockable at the exterior with a key for locking
the normal band crank or the like serving for operating the latch of the lock, whereby
the lock at the inner side of the door has a sliding pin fitted with a hand knob,
through which sliding pin the lock can be locked and unlocked from this side. The
lock itself is not shown in Figures 6 and 7 since this may remain unchanged and may
have any suitable design. However, the above mentioned sliding pin 62 with hand knob
63 is indicated, which is connected through a lever 64 to the door lock in such a
way that in the depressed position of the knob 62 shown in full lines the lock is
latched against operation from the outside, while in the dotted lifted position of
the knob, said locking is removed. The lock with the lever 64 and the sliding pin
62 are accommodated conventionally in the door, while the knob 63 projects through
an opening in the window opening edge 65 of the door.
[0025] The device 61 forms a separate part which is adapted for assembly in the door underneath
the sliding pin 62 in a suitable manner, not further indicated and consequently, if
desired, can also be incorporated in an already existing door.
[0026] The device 61 has a housing 66 with cover 67 and a framework positioned in the housing
consisting of side plates 68 and a transverse wall 69 rigidly connected therewith.
[0027] The safety device 61, as regards its operation in case of immersion in water has
a design analogous to that of the device described on the basis of Figures 2 and 3,
while in Figures 6 and 7 identical parts are indicated with the same reference numerals
as in Figures 2 and 3. The device 61 again has a swelling body 33 accommodated in
a chamber 28, which chamber in the present case is accessible by an access door 70
provided in the cover 67 and projecting along some distance inwardly, while furthermore
holes 30 provided in the housing wall terminate in the chamber 28. The swelling body
acts on the slide 31 guided on pins 32, against which slide is supported the one arm
of the two-armed pivotally mounted catch 43 which on the other end engages in the
opening 44 of the plate 38 guided between the pins 42 and 40, which plate is affixed
to the rear end of the unlocking rod 35. Said rod 35 in the present case is guided
axially slidably through fitting openings in the transverse wall 69 and the upper
wall of the housing 66 and is under pressure of the helical spring 37 which lies enclosed
between the transverse wall 69 and the sleeve 57 secured onto the rod 35. The end
of the unlocking rod 35 in this case projects from the housing 66 in outward direction
and carries a stop head 71 secured thereon, which in the drawn rest position of the
unlocking rod 35 lies with slight play underneath the bottom end of the lock sliding
pin 62 respectively the lever 64 pivotally secured thereon.
[0028] It will be clear that in case through expansion of the swelling body 33 the catch
43 releases the unlocking rod 35,saidrod through the effect of the spring 37 will
be urged upwardly, thereby forcing with its head 71 the lock sliding pin 62 to the
dotted unlocking position.
[0029] On the outwardly projecting end portion of the unlocking rod 35 there is mounted
yet a drip cap 72 engaging about the housing 66, while on the cover 67 above the access
door 70 there is attached a projecting drip edge 73 to prevent any rain or wash water
seeping into the door from attaining the swelling body 33.
[0030] The safety device 61 is designed with a temperature-responsive member which in the
present case comprises a container 73 filled with a medium expandable upon heating
and which is connected through a pipe 74 to a diaphragm box 75 mounted against the
side of the housing 66 of a known per se design. The container or feeler 73 may be
secured in a suitable place against the inner wall of the respective motor-car door,
preferably behind an opening in said door wall covered by a grid or the like. The
diaphragm of the diaphragm box 75 acts through a transmission mechanism 76 on a sliding
rod 77 conducted through the housing wallinto the housing. Against the bottom of the
housing 66 there is secured an assembly plate 78 which has upright supports 79 fitted
with a guide hole for guidance of the sliding rod 77 and similar supports 80, 81 for
the guidance of an unlocking rod 82. On the sliding rod 77 there is mounted a catch
83 which with its bent back end is inserted in a transverse hole 84 of the unlocking
rod 82, thereby retaining said rod in the rest position drawn. On the unlocking rod
82 there acts again a helical spring 85 which lies enclosed between the support 81
and a sleeve 86 secured on the rod 82 and which tries to press the rod 82 upwardly.
At the bottom end of the unlocking rod 82 there is secured a clip 87 which in the
rest position drawn engages with some play about the end of the catch 43 facing towards
the slide 31. On the assembly plate 78 there is formed yet a stop shoulder 88 which
limits the upward movement of the unlocking rod 82.
[0031] When for instance in case of a motor-car fire the medium in the container 73 expands
through heating, the diaphragm of the diaphragm box 75 will press the slide rod 77
inwardly in such a way that at a given, predetermined critical temperature of the
medium, the catch 83 is pressed by the sliding rod 77 from the hole 84 of the unlocking
rod 82. Thus the unlocking rod 82 is pressed upwardly by the spring 85, while the
clip 87 entrains the pivoting catch 43 so that also the unlocking rod 35 is released
and thus, as described in the above, the locking sliding pin 62 of the door lock is
pressed upwardly to the unlocked position.
[0032] Although the safety device described in the above for unlocking or opening a lock
is suitable in particular for application in combination with a buckle fastening for
a safety belt or the lock of a motor-car door, also other favourable applications
are conceivable. For instance, the safety device may be accommodated in the buckle
fastening between the harness of a parachute and the parachute lines, so that this
fastening will be automatically opened when the parachutist arrives in the water.
A temperature-responsive member in that case is not necessary. The latter again is
the case though upon application of the safety device described in combination with
a door lock closable at the inside by a latch or the like of e.g. a door of a hotel
room, so that in case of fire this locking is automatically removed. In general, the
swelling body may be omitted in the latter application.
1. A lock having a locking member displaceable between a locking position and a release
position, characterized in that the lock is provided with a safety device for automatically
unlocking the locking member upon a critical change of a given ambient condition,
which safety device comprises at least one usually unloaded feeler member (33; 47;
73) responsive to the respective change of condition and provided with an unlocking
element (35; 53; 82), which through the effect of a spring (37, 56; 85) is movable
from a retracted rest position, wherein said element does not influence the locking
member of the lock, to an operative position wherein said element displaces the locking
member to the release position, whereby the unlocking element is retained in the rest
position by a catch (43, 52; 83) co-acting with the feeler member, which catch is
actuated when the feeler member responds to a change of condition and then releases
the unlocking element.
2. A lock according to claim 2, characterized in that the feeler member comprises
a liquid-absorbing swelling body (33) which presses the catch (43) to the release
position upon its swelling-up by liquid absorption.
3. A lock according to claim 2, characterized in that the swelling body (33) is enclosed
in a chamber (28) bounded at one side by a slide (31), which slide engages the catch
(43).
4. A lock according to claim 3, characterized in that the catch (43) is rotatably
mounted and has two arms, the one catch arm engaging behind a stop shoulder (44) of
the unlocking element (35), while the other catch arm engages the slide (31) and through
the force of the spring (37) engaging on the locking element keeps the slide pressed
to an inner rest position defined by a stop (32), in such a way that the swelling
body upon expansion through intermediary of the slide can rotate the catch against
spring action until this catch falls from the stop shoulder of the unlocking element.
5. A lock according to any one of the preceding claims, characterized in that the
unlocking element comprises a longitudinally slidably guided unlocking rod (35; 82)
which with its leading end is adapted to act on the lock latching member or a co-acting
part and which at its rear side has opening (44, 59; 84) wherein the catch engages.
6. A lock according to any one of the preceding claims, characterized in that as feeler
member is present a temperature-responsive member (47; 73) which responds to a strongly
increased critical ambient temperature for actuating the catch (52; 83).
7. A lock according to any one of the claims 2-5, characterized in that the lock is
a buckle fastening with snap effect, in particular for a safety belt for motor-cars
or the like, and that the safety device together with the feeler member designed as
a swelling body (33) is accommodated in the buckle housing (1).
8. A lock according to claim 7, wherein the buckle fastening has as locking member
a locking body mounted pivotally in the buckle housing and pressed by a spring to
the closure position, which locking body is adapted to engage in an opening of a buckle
tongue insertible in the buckle housing by an insert slot and which for its unlocking
is adapted to be lifted from said tongue opening by a hand knob-operated lock lifting
rod, characterized in that the unlocking element respectively the unlocking rod (35)
slidably guided in the buckle housing (1) is adapted to engage with its end underneath
an edge of the locking body (15) of the buckle fastening for lifting same.
9. A lock according to claim 6 and 7 or 8, characterized in that the safety device
comprises besides the swelling body (33) also as second feeler member a temperature-responsive
member consisting of a bimetal element (47) accommodated in the buckle housing (1),
which element operates a catch (52) for a separate unlocking rod (53) for the locking
body (15) of the buckle fastening and slidably guided in the buckle housing under
spring pressure.
10. A lock according to any one of claims 1-6, characterized in that the lock is a
door lock, in particular for a motor-car door, of the type that is closable at one
side by a key and at the other side having an actuating member, such as a sliding
pin (62) provided with a hand knob (63), by means of which the lock can be locked
and unlocked from this side, whereby the unlocking element (35) of the safety device
(61) being under spring pressure, upon actuation of said device, actuates the sliding
pin of the door lock when said pin is in the lock latching position.
11. A lock according to claim 10, characterized in that the safety device (61) is
accommodated in a separate housing (66) and the unlocking element comprises a push
rod (35) projecting outwardly from said housing, the head (71) of which lies opposite
the end of the actuating member respectively the lock sliding pin (62) facing away
from the actuating knob (73) for the actuation thereof.
12. A lock according to claim 6 and 11, characterized in that the safety device (61)
comprises besides a swelling body (33) likewise a temperature-responsive member (73)
for unlocking the push rod (35).
13. A lock according to claim 12, characterized in that the temperature-responsive
member comprises a container (73) filled with a medium expanding when heated and connected
through a conduit (74) to a diaphragm box (75) attached to the housing (66) of the
safety device (61), while the diaphragm of said box is coupled to the respective catch
(83).
14. A lock according to claim 12 or 13, characterized in that the unlocking element
(82) added to the temperature-responsive member, upon actuation thereof, acts on the
catch (43) of the push rod (35) actuated by the swelling body (33).
15. A loose safety device for a door lock of a motor-car door according to any one
of claims 10-14.